2 × 128 Silicon Avalanche Photodiode Linear Arrays With High Uniformity

In this letter, we report a high-uniformity
$2\times 128$
silicon avalanche photodiode linear array for 3D imaging. The
$100~\mu \text{m}$
diameter,
$50~\mu \text{m}$
gap pixels incorporate floated guard ring and edge implantation to prevent premature breakdown. Despite the large scale, breakdown voltage uniformity across all 256 pixels exceeds 98.8%. At room temperature, pixels show 0.55 A/W peak responsivity at gain =1 (80% external quantum efficiency at 875 nm) and maximum gain exceeds 550 at 95% breakdown voltage. The array exhibits a 1.6 V deviation in breakdown voltages from 122.8~126 V across pixels, indicating a high uniformity larger than 98.8%. Dark current remains below 60 pA at gain =1 and 300 pA at 90% breakdown voltage per pixel. The capacitance is below 0.4 pF near avalanche. Furthermore, we measured the dark current-voltage characteristic at various temperatures, and a consistently low dark current, at approximately 10 nA, was obtained at a temperature up to 100 °C. These results represent a significant advance for silicon linear arrays in 3D imaging.